Selective radio condenser



Sept. 3, 1929. D. R. WELLS SELECTIVE RADIO CONDENSER Filed June 27, 1927 Patented Sept. 3, 1929.

PATENT OFFICE.

DUDLEY R. WELLS, OF LOS ANGELES, CALIFORNIA.

SELECTIVE RADIO CONDENSER.

Applieation filed June 27,

This invention relates to variable radio condensers in which a pluralit of electrlcal capacity units differing in rate electrical capacity value are employed, 1n order that the electrical capacity or frequency value in radio receiving or transmitting sets may be varied by the operator as occas1on may require.

Some of the objects of the invention contemplate the obtaining of a highly efiicient capacity facility for short wave receivers; a

greater dial sweep, which obviates the necessity of a minute adjustment of the Vern er; a more perfect tuning scope to a given c01l and to obviate the necessity of frequent ad ustment of theplug-in coils which are present in short wave sets.

The above recited and other objects of the invention will be more fully disclosed in the following specification, and will be exemplified in the accompanying drawings, in which;

Figure 1 is a plan view of the device embodying the features of the invention.

' Figure 2 is a front view of the panel upon which the device is secured, showing the condenser operating dial and the switch lmob.

Figure 3 is a section taken on the line 3-3 of Figure 1 viewed in the direction indicated by the arrows.

Figure 4 is a section taken on the line 44 of Figure 1. v

Figure 5 is a section taken on the line 5 of Figure 1.

Figure 6 is a section taken on the line 6-6 of Figure 1.

'5 In carrying out the lnvention, 10 represents the panel of a radio set preferably formed of insulating material, and 11a frame secured thereon on which the various plate units 12, h

13, 14 and 15 are mounted and which in combination with an electrical switch unit 16 the various micro-farad values are obtained.

The frame 11 comprises a pair of opposite disposed walls 17 and 18, preferably formed of insulating material, held together in spaced 45 relation by means of the front and rear walls 19 and 20 and the struts 21.

J ournaled in the walls 19 and 20 is a shaft 22, which projects through an opening in the panel 10 and has secure-d on its end a tuning 50 in dial 23.

Each of the units 12, 13, 14 and 15 comprises the usual stator capacity plates 24, which are supported on, and suitably spaced apart by the blocks 25 which in turn are se- 66 cured by means of screws to the walls 17 and 1927. Serial No. 201,838.

18, and the rotary capacity plates 26 which are secured to the shaft 22 and are adapted to engage between the plates 24.

A spring electrical contact brush 27 is secured to a terminal post 28 projecting from the rear wall 20 and is adapted to wipe against the surface of the shaft 22.

J ournaled in bearing blocks 29 and 30 which are secured respectively to the walls 19 and 20 is a switch shaft 31 which has secured to its front end a dial or knob 32 provided with the indicator arrow 33 adapted to point to the Vernier graduations 34 on a disc 35 secured to the panel 10. Secured to the shaft 31 are the discs 36, 37, 38 and 39 arranged respectively opposite the units 12, 13, 14 and 15 and provided with the contact buttons 40.

'The contact buttons 40 are adapted to engage with the spring contact clips 41, 42, 43 and 44 secured to the wall 17 by means of the screws 45, 46, 47 and 48 and which respectively form electrical connection with the plates 26 of units 12, 13, 14 and 15 as clearly shown in Figure 1, of the drawings.

A contact brush 49 which extends from a binding post 50, secured to the arm 30, is adapted to wipe the surface of the shaft 31.

The binding posts 28 and 50 are connected by means of the wires 51 and 52 to a source of electrical energy (not shown) in order that when any of the buttons 40 are in contact with the clips 41, 42, 43 and 44 electrical circuits will be formed through their associated plate units.

Each plate unit 12, 13, 14 and 15 marked respectively A. B. C. and D. is designed to ave a different micro-farad capacity and these and combinations of the same, determined by the placements of the buttons 40 on the switch disc are marked on the dial 35. thus it will be seen that by a manipulation of the knob 32 the desired capacity may be attained. As shown in the drawing both C. and D. are in circuit and consequently the con denser has the combined capacity of these two plate units.

Having thus described my invention what I claim is:

1. A condenser comprising a frame having a plurality of condenser units of different capacities composed of stator capacity plates and rotor capacity plates mounted thereon; a contact clip for each unit and connected to the stator capacity plates thereof; a shaft mounted for rotation on said frame having discs secured thereon disposed opposite said clips; contact buttons on said discs adapted to en age with said clips and means for making eictrical connection with said discs and said stator capacity plates.

.2. A condenser comprising a frame having a plurality of condenser units of diiierent capacities composed of stator capacity plates 10 and rotor capacity plates mounted thereon;

contact making means for each unit and connected to the stator capacity plates thereof;

a shaft mounted for rotation on said frame carrying a plurality of switch'elements to cooperate with said contact making means; contact members on said switch elements adapted to engage with said contact making means; and means for making electrical connection with said switch elements and said stator capacity plates.

In testimony whereof I hereunto aflix my slgnature.

DUDLEY R. WELLS. 

